This invention relates to fluid connectors, and more particularly to a multi-line hydraulic connector adapted for use in a tool coupler used with excavation, demolition and construction equipment.
Some types of construction equipment, such as backhoes or excavators, include a movable dipper stick (also referred to as an arm) to which a variety of tools, such as buckets, grapples, hammers and the like, can be attached. A hydraulic bucket cylinder coupled to the attached tool at a link pivot rotates the tool about a dipper pivot at the free end of the dipper stick. The bucket cylinder and a linkage to the link pivot are located on a distal (forward) side of the dipper stick relative to the cab where the operator sits. To simplify the process of changing tools, a tool coupler can be permanently attached to the dipper pivot and the link pivot. A selected tool can then be removably attached to the coupler with a locking mechanism. The locking mechanism, in some cases, includes a locking pin on the tool coupler that engages a mating receptacle in the tool.
There is a trend in the industry to use an actuated quick-disconnect tool coupler for automatically connecting and disconnecting a tool. Co-owned U.S. Pat. No. 5,727,342, to Horton, describes a quick-disconnect tool coupler that includes a latch pin biased by a spring to a forward locking position. The latch pin is retracted by extending a hydraulic latch pin cylinder located in the coupler. With this type of tool coupler, the equipment operator can switch tools without leaving the cab of the equipment.
Some tools include a hydraulically actuated mechanism. For example, some grapple attachments include a hydraulic cylinder for opening and closing the grapple jaws. The tool hydraulics typically require two hydraulic connections between the tool hydraulics and hydraulic lines extending to the end of the dipper stick. In presently available systems, these connections must be made manually. This reduces the efficiencies of the hydraulically actuated quick-disconnect tool coupler systems, because the equipment operator must leave the cab to make the connections or a second worker must be available to do so.
The invention generally features a non-spill, multi-line fluid connector with a plurality of separate, substantially coaxial flow paths. The fluid connector can be incorporated into a latch pin assembly of a quick-connect tool coupler in a manner that does not compromise the latching mechanism of the quick coupler. The latching mechanism includes a latch pin in the tool coupler and a latch bracket that receives the latch pin in the tool. The latch pin is spring applied, and hydraulically released from the latch bracket. Each of the latch pin and latch bracket includes longitudinally movable internal parts that provide a pair of coaxial fluid channels. These parts cooperate when the latch pin is inserted into the latch bracket to provide connections between the pairs of channels.
The invention allows tools and existing couplers to be easily converted to the new system. An equipment operator can connect a hydraulically actuated tool to the tool coupler, including all hydraulic connections, without leaving the cab of the equipment. The fluid connector includes a locking mechanism that enhances the overall safety of the equipment by inhibiting accidental release of the hydraulic tool when pressure is hydraulic pressure is applied to hydraulic actuator in the tool.
According to one aspect of the invention, a fluid connector comprises a first part having a distal end and a second part having a proximal end adapted to be removably connected with the distal end of the first part, the first part comprising first and second fluid channels extending within the first part from respective first and second end seals at the distal end and coupling to respective first and second fluid ports, the end seals closing off the first and second fluid channels when the first part and the second part are disconnected, the second part comprising first and second fluid channels extending within the second part from respective first and second end seals at the proximal end and coupling to respective first and second fluid ports, the end seals of the second part closing off the first and second fluid channels of the second part when the first part and the second part are disconnected, wherein connecting the first part and the second part connects the first fluid channels of the first and second parts and also connects the second fluid channels of the first and second parts, and the second part further comprising a locking mechanism having a first, locking position that inhibits separation of the first part and the second part and a second, releasing position that permits separation of the first part and the second part, the locking mechanism comprising an annular locking member urged toward the first, locking position by fluid pressure applied through the first part and the second part.
Preferred embodiments of this aspect of the invention may include one or more of the following additional features. The annular locking member comprises a split ring. The annular locking member is disposed for rotational displacement relative to the outer surface of the latch pin and/or the annular locking member is disposed for radial displacement relative to the outer surface of the latch pin. Preferably, the annular locking member is disposed for non-uniform radial displacement relative to the outer surface of the latch pin. The annular locking member is urged toward the first, locking position of the locking mechanism by one or more elongated regions of surface-to-surface contact.
According to another aspect of the invention, a latch bracket for attachment to a hydraulically operated tool having a hydraulic mechanism comprises a first fluid channel extending therethrough, with a first port coupled to the first fluid channel for coupling the first fluid channel to the hydraulic mechanism, and a second fluid channel extending therethrough, with a second port coupled to the second fluid channel for coupling the second fluid channel to the hydraulic mechanism, wherein the latch bracket is adapted to receive a male latch pin on a tool coupler to lock the tool to the tool coupler and to couple the first fluid channel to a first source of hydraulic pressure and to couple the second fluid channel to a second source of hydraulic pressure, through the latch pin, and the latch bracket further comprises a locking mechanism that inhibits the latch pin from retracting out from the latch bracket while fluid pressure is applied through the latch pin to the latch bracket.
Preferred embodiments of this aspect of the invention may include one or more of the following additional features. The second fluid channel comprises an outer fluid channel concentrically surrounding the first fluid channel. The first fluid channel comprises a substantially annular inner fluid channel. The latch bracket further comprises an inner proximal o-ring positioned to provide a seal at a proximal end of the inner channel of the latch bracket and an outer proximal o-ring positioned to provide a seal at a proximal end of the outer channel of the latch bracket when a latch pin is disconnected from the latch bracket, the inner proximal o-ring and the outer proximal o-ring being arranged to unseal when a latch pin is connected to the latch bracket. Preferably, the latch bracket further comprises a body, including a cylindrical bearing at a proximal end adapted to receive and guide the latch pin, and an end cap at a distal end; an elongated plunger extending proximally from the body a first distance, including an outwardly sloped surface near a proximal end, and a proximal end face that first contacts a distal end of the latch pin when the latch pin is inserted into the cylindrical bearing, wherein the outwardly sloped surface comprises an o-ring groove in which the inner proximal o-ring is positioned; a substantially annular inner section member extending proximally from the body a second distance that is less than the first distance, wherein the inner section member includes a cylindrical surface and is arranged substantially concentrically around the plunger providing a gap therebetween; a substantially annular outer section member extending proximally from the body a third distance that is less than the first distance and greater than the second distance, wherein the outer section member includes a cylindrical surface and is arranged concentrically around the inner section member providing a gap therebetween; an inner sleeve comprising an inner surface having an outwardly sloped portion at a proximal end adapted to fit against the outwardly sloped surface of the plunger, the first proximal o-ring providing a seal therebetween when the latch bracket is disconnected from the latch pin; an outer surface having an outwardly sloped portion near a distal end that includes an o-ring groove in which the outer proximal o-ring is positioned; and a cylindrical surface at a distal end that slidingly engages with the cylindrical surface of the inner section member, wherein the inner channel is defined by the plunger, an inner surface of the inner section member and the inner surface of the inner sleeve; a inner middle o-ring providing a seal between the cylindrical surface of the inner section member and the cylindrical surface of the bracket inner sleeve; a second sleeve, comprising: an inner surface having an outwardly sloped portion at a proximal end adapted to fit against the outwardly sloped surface of the outer surface of the inner sleeve, the outer proximal o-ring providing a seal therebetween when the latch bracket is disconnected from the latch pin; and a cylindrical surface at a distal end that slidingly engages with the cylindrical surface of the inner section member, wherein the outer channel is defined by an outer surface of the inner section member, the outer surface of the inner sleeve, the inner surface of the second sleeve, and an inner surface of the outer section member; an outer middle o-ring arranged to seal between the cylindrical surface of the outer section member and the cylindrical surface of the second sleeve; and a bias member arranged to urge the second sleeve proximally against the inner sleeve and the inner sleeve against the plunger. The locking mechanism includes a shuttle valve having first and second inlets coupled to the inner and outer channels, respectively, and an outlet; an outer sleeve arranged adjacent a middle section of the body which is located between the end cap and the cylindrical bearing, the outer sleeve and the middle section defining an annular chamber coupled therebetween, the outer sleeve comprising an inner cylindrical surface having a diameter approximately the diameter of the cylindrical bearing to receive a distal end of the latch pin; a fluid channel connecting between the outlet and a distal end of the chamber; an annular shaped locking block within the annular chamber that is arranged to slide longitudinally therein to a proximal position when fluid pressure is applied to the chamber through the output; and an annular locking member arranged for deflection radially inwardly from the inner cylindrical surface of the outer sleeve when the locking block moves to the proximal position to engage the annular locking member in an annular groove formed on an outer surface of the latch pin. The latch bracket further comprises a fluid switch between the first fluid channel and the second fluid channel that closes when the latch pin is connected to the latch bracket to equalize pressures between the first fluid channel and the second channel, and that opens when the latch pin is connected to the latch bracket. The latch bracket further comprises a backing piece that includes the inner section member, the outer section member and an opening therebetween, wherein the backing piece is capable of moving a small lateral distance from a central axis of the latch bracket.
In other features, the second part may further include a locking mechanism that inhibits the pin body from moving away from the second part while fluid pressure is applied through the first part and the second part. The first part can include a fluid switch arranged to turn on to weakly couple fluid pressure in the central channel with fluid pressure in the outer channel when the first part is disconnected from the second part, and to turn off to decouple fluid pressure in the central channel with fluid pressure in the outer channel when the first part is connected to the second part. The second part may also include a fluid switch arranged to turn on to weakly couple fluid pressure in the inner channel with fluid pressure in the outer channel when the first part is disconnected from the second part, and to turn off to decouple fluid pressure in the inner channel with fluid pressure in the outer channel when the first part is connected to the second part. The second part can have a distal end cap, which includes the first and second ports of the second part, a first connecting channel communicating between the first port and the inner channel of the second part, and a second connecting channel communicating between the second port and the outer channel of the second part. The second part may also have a backing piece, which includes the inner section member, the outer section member and an opening there-between. The backing piece is capable of moving a small lateral distance from a central axis of the second part.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.